Manipulation therapy alleviates neuropathic pain via the SOCS1 m⁶A epigenetic loop

Manipulation therapy (MT) relieves pain in nervous system disorders by reducing inflammation. Although evidence suggests MT is beneficial for neuropathic pain (NP), its molecular mechanisms remain unclear. This study investigated whether MT could reverse NP-related epigenetic changes and elucidated the potential mechanisms of NP.

An NP model was established via spinal nerve ligation (SNL), and MT was administered at acupoints Jumping Round (GB30), Yang Mound Spring (GB34), and Suspended Bell (GB39) for 14 days. Mechanical and thermal pain in rats were evaluated using the mechanical paw withdrawal threshold and thermal paw withdrawal latency tests. Inflammatory cytokine levels in spinal cord neurons were quantified using enzyme-linked immunosorbent assay. Total N⁶-methyladenosine (m⁶A) levels were assessed by colorimetric analysis, while target genes were validated using methylated RNA immunoprecipitation succeeded by quantitative polymerase chain reaction, immunofluorescence, Western blotting, and quantitative real-time polymerase chain reaction.

The outcomes indicated that MT significantly attenuated SNL-induced pain hypersensitivity. The therapeutic effects of MT were correlated with global m⁶A methylation in spinal cord neurons. Moreover, MT affected the toll-like receptor 4 (TLR4) signaling pathway's expression by modulating suppressor of cytokine signaling 1 protein (SOCS1) mRNA m⁶A methylation levels, consequently reducing the secretion of neuroinflammatory cytokines interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α), thereby alleviating NP.

This study provides evidence that MT effectively ameliorates NP by modulating inflammation and RNA m⁶A methylation in the spinal cord via the SOCS1/TLR4 pathway.